The present invention relates to boat-lift systems and methods and, more particularly, to boat-lift systems and methods adapted to lift a small boat out of the water for stowage on a larger boat.
Operators of relatively large boats (i.e., over twenty-five feet long) often use smaller, more mobile boats for certain activities or to reach locations not accessible to the larger boats. When not in use, these smaller boats are often stowed aboard the larger boat.
A number of systems are known for lifting a smaller boat out of the water and into a storage position on a larger boat. One such system will be referred to herein as a davit system. A davit system comprises two uprights that are swung out over the side of the larger boat to raise and lower the smaller boat. With the smaller boat in the raised position, the uprights are typically swung back to place the smaller boat in a stowed position. Davit systems occupy a substantial amount of deck area on the larger boat and are relatively complex and expensive.
A swim step is typically mounted to the transom of larger boats. The swim step comprises a flat step surface supported just above the water line. An operator can stand on the step surface when accessing, entering, or exiting the water. Some boat-lift systems make use of the swim step as support for the lift system and/or as a storage location for the smaller boat. For example, a winch may be mounted at the stern of the larger boat. The winch is connected to cables that extend around the smaller boat, and operation of the winch displaces the cables to lift the smaller boat onto the swim step. Swim steps are not necessarily designed to accommodate the weight of the smaller boat, and the winches and cables can interfere with use of the stern and swim step of the larger boat.
The following references were turned up in a professional patentability search conducted on behalf of the Applicant.
U.S. Pat. No. 5,937,783 to Costa, U.S. Pat. No. 5,483,912 to Thomas, U.S. Pat. No. 5,193,479 to Bielefeld, U.S. Pat. No. 5,133,275 to Maurizio, and U.S. Pat. No. 4,864,951 to Koepp, Jr. all teach davit systems for hoisting small boats onto a swim platform of a larger boat. In each of these patents, a member or assembly is rotatably attached to the end of the swim platform distal from the larger boat. All of these systems use cables to pull either the boat or the rotatable member or assembly from a loading position to a storage position.
U.S. Pat. No. 3,647,089 to Christiansen patent describes a system that it is pivotably supported by a swim step mounted on the transom of a larger boat. However, the device disclosed in the Christiansen patent employs bumpers that engage the side of the smaller craft and a frame that extends over the top of the smaller craft. The smaller craft is lifted from above rather than from below. The Christiansen device also employs winches and cables, is supported by the swim step, and obstructs access to the swim step.
U.S. Pat. No. 4,627,377 to Zooens, U.S. Pat. No. 6,327,992 to Martin, U.S. Pat. No. 5,636,587 to Klimowicz, and U.S. Pat. No. 4,763,593 to Lasko disclose davit systems that are pivotably connected at a pivot point at or near the transom of a larger boat. The systems disclosed in these patents rotate between loading and stored positions in a manner that would inhibit the use of a conventional swim platform.
The Applicant is further aware of a boat-lift product sold under the tradename FreedomLift. The FreedomLift product employs a pivot point adjacent to the transom of the larger boat. A lift structure extends from the pivot point and is moved between upper and lower positions to raise and lower the smaller boat to the rear of the swim step.
The present invention may be embodied as a boat-lift system adapted to move a smaller boat relative to a larger boat. Typically, a swim step is secured to the stern of the larger boat, and the swim step defines an aft edge and a swim step surface. The boat-lift system comprises a structural support, a lift structure, a pivot system, and an actuator assembly.
The structural support defines a first pivot portion and is adapted to be rigidly connected to the transom of the larger boat. So connected, the first pivot portion is arranged below the swim step surface and forward of the aft edge of the swim step. The lift structure defines a second pivot portion, an actuator portion, an extension portion, and first and second boat-engaging portions extending from the extension portion. The pivot system connects the first and second pivot portions to allow rotation of the lift structure between first and second lift positions relative to the structural support. The actuator assembly is secured at a first end relative to the structural support and at a second end to the actuator portion of the lift structure. Actuation of the actuator assembly in a first mode causes the lift structure to move from the second lift position to the first lift position.
When the lift structure is in the first lift position, the first boat-engaging portion extends over the swim step surface and the second boat-engaging portion extends rearwardly beyond the aft edge of the swim step. When the lift structure is in the second lift position, the first boat-engaging portion is spaced rearwardly of the aft edge of the swim step surface and the second boat-engaging portion extends below the first boat-engaging portion.
Accordingly, when the smaller boat is in a docking position adjacent to the lift structure and the actuator assembly is operated in the first mode, the lift structure moves the smaller boat from the docking position to a first storage position relative to the larger boat.
The lift structure may further be an assembly comprising a pivot member and a lift member. The pivot member defines the pivot portion, the actuator portion, and a socket portion. The lift member defines the extension portion and the first and second boat-engaging portions. The lift member is detachably attached to the pivot member to allow the lift member to be removed and stored when the boat-lift system is not in use.
The present invention may be embodied as a method comprising the steps of providing a structural support, a lift structure, a pivot system, and an actuator assembly and connecting and operating these structural elements.